Timepiece



1936- E. o. SCHWEHTZER, JR 2,061,047

TIMEPIECE Filed Dec. 17, 1932 Patented Nov. 17, 1936 UNITED STATESPATENT OFFICE 11 Claims.

The present invention relates to timepieces, and more particularly tothe means for controlling the escapement of mechanical timepieces suchas clocks, watches chronometers, or other time controlled movements.

It is an object of the present invention to provide an escapementcontrol which shall be independent of gravity, whereby the control maybe mounted in any position, and which shall be inexpensive and notrequire the delicate balancing required of the usual type of hair springcontrolled balance wheel.

Timepieces of various kinds employing a mechanical mechanism also havesome form of oscillator controlling the rate at which a spring or weightactuator is permitted to release its energy. This oscillator may takethe form of a pendulum or a balance wheel and hair spring. Pendulums, tobe accurate, require a fixed position of the timepiece. Balance wheelsrequire a delicate construction with a delicate spring to store energyfor the return movement. The balance wheel must be balanced so that itsperiod of oscillation is not altered by change of position. Balancewheels are expensive and delicate and depend for their operation on aspring which is easily damaged. The spring is affected by externalmagnetic influences and also by temperature.

It is an object of this invention to improve very substantially theoperation of such time mechanisms, and I do this first by theimprovement of the oscillator, since it is this member that is mostlikely to become deranged and subject to error.

I have replaced the pendulum which has the objections above enumeratedby a mechanism which can be used in watches, clocks, or the like andwhich is not subject to the necessity for a fixed position, is notsubject to expansion and contraction to alter its effect, and which isnot subject to wear and tear due to motion of the clock parts. Iaccomplish this improvement by using an escapement control whichcomprises a small permanent magnet which acts on a similar magnetmounted on the spindle on which the pendulum is usually mounted. Thisconstitutes, in effect, the replacement of the usual bob on a pendulumby a permanent magnet, and the replacement of gravityby a secondpermanent magnet. The stationary magnet can be adjusted toward and awayfrom the oscillating magnet to change the rate of oscillation of theoscillating magnet and thereby regulate the action of the timepiece.

I have found that my magnetic oscillator will permit the operation ofthe timepiece in any position and. that the change of strength ofmagnetism can be made practically insensitive to temperature changes orto changes with time.

My present invention is particularly adapted for use on automobiles orin places subject to vibration or shock such as would derange thesymmetry of the usual hair spring, or affect the clock on account of thevibration of the hair spring of the balance wheel. It is well known thatclocks or watches used on the panel of automobiles fail to keep time ofeven the roughest accuracy. My present invention provides a much neededimprovement in clocks that are intended for such use.

The attainment of theabove and further objects of the present inventionwill be apparent from the following specification taken in con junctionwith the accompanying drawing forming a part thereof.

In the drawing:

Figure 1 is a view of a clock gear train, showing the escapement and myimproved control means therefor; and

Figure 2 is a fragmentary isometric view illustrating a modification ofmy invention.

In Figure 1 I have shown my invention applied to a clock mechanism of astandard construction wherein a clock spring 10 furnishes the drivingpower for driving the clock hands II and [2 through the usual gear trainunder the control of an escapement wheel IS. The escapement iscontrolled by pallets or pins I1 and I8 on an oscillating member IS inthe usual manner, well known in the art. My present invention isconcerned with the means for controlling the oscillation of the memberl9 to control the timing of the clock. In the prior practice it has beencustomary to control the member l9 by means of a pendulum, in the caseof clocks, or by a balance wheel and hair spring, in the case of watchesor of wall clocks not provided with a pendulum. Pendulums, or balancewheels and hair springs, are subject to the-objections previously noted.In accordance with my invention I eliminate the gravity controlledpendulum as well as the balance wheel and hair spring. This isaccomplished in the following manner: The oscillating member I9 iscontrolled by another oscillating member which corresponds to a pendulumbut is not gravity controlled. This other oscillating member comprises arod 20 secured to a spindle 2| that carries the oscillator I9. The rod20 is provided with a permanent magnet 23 at one end and a counterweight24 at its other end. The permanent magnet and the counterweight are soarranged that the center of gravity of the oscillating system comprisingthe rod 25 with its magnet and its counterweight is exactly at thecenter of the spindle 2|. The permanent magnet 23 oscillates through asmall arc in the field of another permanent magnet 25. The adjacentfaces of the magnets 23 and 25 are of opposite polarity. The magnet 25is screw threaded and is mounted upon a brass nut 26 that is secured toone of the uprights 21 of the frame supporting the clockwork. The magnet25 may be adjusted toward and away from the magnet 23 to alter the forceof attrac tion between the magnets 23-25 and thus alter the naturalperiod of oscillation of the oscillating rod 20. It may be seen thatwhat I have done in the present case is to replace the ordinary pendulumbob by a permanent magnet and have replaced gravity by a secondpermanent magnet. In view of this I am able to counrestoring force ofthe magnetic field between the stationary magnet 25 and the movablemagnet 23 exerts a restoring force upon the magnet 23 and its connectedsystem tending at all times to move the magnet towards its central orneutral posi-' tion. This restoring force increases as displacementincreases, and the ratio of the restoring force to displacement does notdecrease as displacement increases, but either remains constant orpreferably increases as in the case of a gravity pendulum.

It is apparent that the permanent magnet 25 need not be located normounted in the manner indicated. The permanent magnet 25 may be locatedanywhere adjacent the permanent magnet 23 so as to place the permanentmagnet 23 in the field of the magnet 25. By moving the permanent magnet25 closer to or farther from the magnet 23 the natural period ofoscillation of the rod 20 is varied. This is fundamentally differentfrom the manner of regulating a pendulum clock wherein the bob is movedtoward or away from the center of oscillation to vary the natural periodof the pendulum. In eilect, I vary the gravitational force rather thanthe length of the pendulum.

In Figure 2 I have shown a modified form of magnetic control. The magnet23' corresponds to the magnet 23 of Figure 1 and is of a generallychannel or C-shape. The magnet 25' corresponds to the magnet 25 ofFigure 1 and is also of a generally or channel-shape. The poles of themagnets 23' and 25 are 01' the polarities indicated in the drawing sothat the upper poles of the two magnets are of opposite polarity and thelower poles of the two magnets are of opposite polarity, whereby themagnet 25' always attracts the magnet 23. It is to be noted that themagnet 25' is of a substantially greater length than the magnet 23 sothat the field of this magnet is substantially constant throughout therange of oscillation of the magnet 23. On each side of the magnet 23',and within the proximity of the extreme limits of oscillation of themagnet 23', I have placed two permanent magnets 33 and 3|. When themagnet 23' oscillates in one direction the shoes thereof move adjacentthe upper and lower shoes of the permanent magnet 30, and when themagnet 23 oscillates in the opposite direction the shoes thereof moveadjacent the upper and lower shoes of the permanent magnet 3|. The upperpole shoes 0! the magnets 33 and 3 I are of the same polarity as theupper pole shoe of the magnet 23', and the lower pole shoes of themagnet 35 and 3| are of the same polarity as that of the lower pole shoeof the magnet 23'. Thus the magnets 33 and 3| repel the magnet 23',whereas the magnet 25' attracts the magnet 23. The force of repulsion ofthe magnets 35 and 3| increases as the arc of oscillation of the member20 increases so that the greater the arc of oscillation the greater willbe the accelerating force of the magnet 23' as it starts moving fromeither extreme position. By 'this arrangement a greater arc of travel,results in a higher speed of travel so that the periodicity of themember 20 remains substantially constant regardless of the length ofswing, within the limits of motion of the oscillating member. By thisarrangement a variation of the tension of the spring i0, as the clockruns down, does not affect the accuracy of the time piece. The magnet 25may be adjusted toward and away from the magnet 23' in any desiredmanner in order to adjust the natural period of oscillation of themember 20. Likewise, the magnets 30 and 3| may, if desired, be mountedso as to permit their adjustment.

While I have herein spoken of an adjustment of the magnetic field byvarying the position of the permanent magnet 25 or 25, as the case maybe, the equivalent result may be obtained by moving a variable magneticshunt into and out of the region of the permanent magnet 25 or 25' andthereby vary the effect of the field of that magnet with respect to theoscillating permanent magnet.

If desired, the permanent magnet 25 may be entirely omitted, relyingexclusively upon the magnets 30 and 3|. In such case it is essentialthat means be provided for adjusting the fields of the magnets 30 and 3|in order to regulate the action of the time piece. This varying eflfectcan be produced by bringing those magnets closer together or fartherapart, or by moving a variable shunt into the region of the fieldproduced by those magnets.

While I have herein shown my invention applied to a clock it is equallyapplicable to other time controlled mechanism employing an escapement.

In compliance with the requirements of the patent statutes I have hereinshown and described a few preferred embodiments of my in vention. It ishowever to be understood that the invention is not to be limited to theprecise arrangement shown, the same being merely illustrative. What Iconsider new and desire to secure by Letters Patent is:

1. An escapement including an oscillating member, a permanent magnetmounted thereon, and means establishing a magnetic field in the path ofmovement of the magnet for controlling the rate of oscillation of themember, said last means including a pair of permanent magnets, one eachof said pair of magnets being located adjacent each of the oppositeextreme positions of oscillation of the first magnet and arranged withpoles of like polarity in position to react with a like pole of thefirst magnet.

2. An escapement including an oscillating member, a permanent magnetmounted thereon, and means establishing a magnetic field in the path ofmovement of the magnet for controlling the rate of oscillation of themember, said last means including a stationary permanent magnet adjacent the first magnet in its mid position, and

a pair of permanent magnets, one each of said pair of magnets beinglocated adjacent each of the opposite extreme positions of oscillationof the first magnet and arranged with poles of like polarity in positionto react with a like pole of the first magnet.

3. An escapement including a permanent magnet, and permanent magnetsbetween which said first named magnet oscillates, said permanent magnetsbeing arranged with poles of like polarity in position to react with alike pole of the first mentioned magnet, whereby the second mentionedmagnets repel the first mentioned magnet to a mid position with forcesthat increase as the amplitude of swing of the first magnet increases. V

4. An escapement oi the type including an oscillating member maintainedin oscillation by periodically received impulses and. having meansbiasing it to a position substantially midway between its extremepositions during oscillation, and wherein the biasing means acceleratesthe member as it moves towards its biased position, said member beingmoved past its biased position by its own inertia and decelerated by thebiasing means as it moves past its biased position, characterized inthat the biasing means comprises a permanent magnet forming a part ofthe oscillating system, and other permanent magnet means coactingtherewith, said last named magi net means comprising a magnet forattracting the magnet of the oscillating system and other magnets forrepelling the magnet of the oscillating system.

5. An escapement of the type including an oscillating member maintainedin oscillation by periodically received impulses and having meansbiasing it to a neutral position substantially midway between itsextreme positions during oscillation, and wherein the biasing meansaccelerates the member as it moves towards its neutral position, saidmember being moved past its neutral position by its own inertia anddecelerated by the biasing means as it moves past its neutral position,characterized in that the biasing means comprises a permanent magnetforming a part 01 the oscillating system, and other permanent magnetmeans coacting therewith, said other magnet means comprising a pair ofmagnets one each being located closer to at least one extreme positionreached by the oscillating member than to the mid position of .theoscillating member and being arranged with poles of like polarity inposition to react with a like pole of the first mentioned magnet and,whereby the force of bias urging the member to its mid positionincreases as the amplitude of oscillation of the member increases.

6. An escapement including a rotating member, an oscillating membercontrolling the rotating member, a supporting member mounted on andconjointly oscillating with said oscillating member, a magnet carried bysaid supporting member and movable in an arcuate path upon oscillationthereof, a counterweight carried by said supporting member. said magnetand counterweight being so arranged with respect to said supportingmember that the center of gravity the oscillating system will be locatedat substantially the point of connection or said supporting member withsaid oscillating member, and means establishing a magnetic field in thepath or movement of said magnet for controlling the rate of oscillaetion of said oscillating member, said last named means imposing arestoring torque on said oscillating member which increases withincreases in amplitude of oscillation of said oscillating member at aratio not less than a predetermined value.

7. An escapement including a rotating member, an oscillating pendulummember controlling the rotating member and comprising a rod pivotedintermediate its ends, a magnet carried by one end of said rod, 9.counterweight on the other end of said rod, said magnet andcounterweight being arranged with respect to the ends of said rodwhereby the center of gravity of the oscillating system will be locatedsubstantially at the pivot point of said rod, and means establishing amagnetic field in the path of movement of said magnet for controllingthe rate of oscillation of said oscillating member which magnetic fieldprovides a force for restoring the magnet from a displaced positiontowards neutral position, which force increases with the displacement,the ratio or restoring force to displacement remaining constant orincreasing with increase in displacement.

8. An escapement comprising a rotating memher and an oscillating membercontrolling rotation of said rotating member, a magnet on saidoscillating member, magnetic means disposed adjacent the arcuate path ofmovement of said magnet on said oscillating member for controlliim therate of oscillation thereof, said magnetic means being so arranged withrespect to said oscillating member as to provide a restoring force onsaid member increasing with increases in the displacement of saidoscillating member the restoring force increasing at least as fast asdisplacement as displacement proceeds.

9. An escapement comprising a rotating member and a magnetic pendulumpivotally mounted to control the rotation of said rotating member, andmagnetic means disposed adjacent the arc of movement of said pendulumand coacting to produce a restoring force on said pendulum whichincreases with increases in the displacement of said pendulum forcontrolling its rate of oscillation the restoring force increasing atleast as rapidly as displacement as displacement proceeds.

10. An escapement comprising a'rotating member and a pivotedmagnetically controlled pendulum having a magnet fixed at one endthereof, and fixed magnetic means for producing oscillation of saidpendulum disposed adjacent the arc of movement of said pendulum magnet,the fixed magnetic means and the magnet on the pendulum cooperating toprovide a restoring force acting upon the pendulum which force increaseswith the displacement of the pendulum from central position at no lessthan a predetermined rate.

11. An escapement comprising a rotating member and a pendulum havingescapement means controlling the rate of rotation of said member inaccordance with the rate of oscillation oi said pendulum, a magnetcarried by said pendulum,

and magnetic means mechanically free of said

